In vertebroplasty, the surgeon seeks to treat a compression fracture of a vertebral body by injecting bone cement such as PMMA into the fracture site. FIG. 1 discloses a conventional fractured vertebral body possessing (dotted) fracture lines. In one clinical report, Jensen et al., AJNR: 18 Nov. 1997, Jensen describes mixing two PMMA precursor components (one powder and one liquid) in a dish to produce a viscous bone cement; filling 10 ml syringes with this cement, injecting it into smaller 1 ml syringes, and finally delivering the mixture into the desired area of the vertebral body through needles attached to the smaller syringes.
U.S. Pat. No. 6,348,055 (“Preissman”) reports that the use of syringes to deliver bone cement in vertebroplasty procedures leads to high pressure spikes. Preissman discloses using a screw-type high pressure injection device to provide an even injection pressure during delivery of the bone cement.
In general, conventional vertebroplasty technology has used a bolus non-resorbable PMMA as a means of stabilizing the fracture. However, this technique does not promote bone regeneration.
Although there have been some efforts to regenerate the bone at the fracture site, these effort have been largely restricted to the use of a bolus of resorbable CaP cement.